view tests/test-pull-r.t @ 33289:abd7dedbaa36

sparse: vendor Facebook-developed extension

Facebook has developed an extension to enable "sparse" checkouts -
a working directory with a subset of files. This feature is a critical
component in enabling repositories to scale to infinite number of
files while retaining reasonable performance. It's worth noting
that sparse checkout is only one possible solution to this problem:
another is virtual filesystems that realize files on first access.
But given that virtual filesystems may not be accessible to all
users, sparse checkout is necessary as a fallback.

Per mailing list discussion at
https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-March/095868.html
we want to add sparse checkout to the Mercurial distribution via
roughly the following mechanism:

1. Vendor extension as-is with minimal modifications (this patch)
2. Refactor extension so it is more clearly experimental and inline
   with Mercurial practices
3. Move code from extension into core where possible
4. Drop experimental labeling and/or move feature into core
   after sign-off from narrow clone feature owners

This commit essentially copies the sparse extension and tests
from revision 71e0a2aeca92a4078fe1b8c76e32c88ff1929737 of the
https://bitbucket.org/facebook/hg-experimental repository.

A list of modifications made as part of vendoring is as follows:

* "EXPERIMENTAL" added to module docstring
* Imports were changed to match Mercurial style conventions
* "testedwith" value was updated to core Mercurial special value and
  comment boilerplate was inserted
* A "clone_sparse" function was renamed to "clonesparse" to appease
  the style checker
* Paths to the sparse extension in tests reflect built-in location
* test-sparse-extensions.t was renamed to test-sparse-fsmonitor.t
  and references to "simplecache" were removed. The test always skips
  because it isn't trivial to run it given the way we currently run
  fsmonitor tests
* A double empty line was removed from test-sparse-profiles.t

There are aspects of the added code that are obviously not ideal.
The goal is to make a minimal number of modifications as part of
the vendoring to make it easier to track changes from the original
implementation. Refactoring will occur in subsequent patches.

  $ hg init repo
  $ cd repo
  $ echo foo > foo
  $ hg ci -qAm 'add foo'
  $ echo >> foo
  $ hg ci -m 'change foo'
  $ hg up -qC 0
  $ echo bar > bar
  $ hg ci -qAm 'add bar'

  $ hg log
  changeset:   2:effea6de0384
  tag:         tip
  parent:      0:bbd179dfa0a7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add bar
  
  changeset:   1:ed1b79f46b9a
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change foo
  
  changeset:   0:bbd179dfa0a7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add foo
  
  $ cd ..

don't show "(+1 heads)" message when pulling closed head

  $ hg clone -q repo repo2
  $ hg clone -q repo2 repo3
  $ cd repo2
  $ hg up -q 0
  $ echo hello >> foo
  $ hg ci -mx1
  created new head
  $ hg ci -mx2 --close-branch
  $ cd ../repo3
  $ hg heads -q --closed
  2:effea6de0384
  1:ed1b79f46b9a
  $ hg pull
  pulling from $TESTTMP/repo2 (glob)
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 1 changes to 1 files
  (run 'hg update' to get a working copy)
  $ hg heads -q --closed
  4:00cfe9073916
  2:effea6de0384
  1:ed1b79f46b9a

  $ cd ..

  $ hg init copy
  $ cd copy

Pull a missing revision:

  $ hg pull -qr missing ../repo
  abort: unknown revision 'missing'!
  [255]

Pull multiple revisions with update:

  $ hg pull -qu -r 0 -r 1 ../repo
  $ hg -q parents
  0:bbd179dfa0a7
  $ hg rollback
  repository tip rolled back to revision -1 (undo pull)
  working directory now based on revision -1

  $ hg pull -qr 0 ../repo
  $ hg log
  changeset:   0:bbd179dfa0a7
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add foo
  
  $ hg pull -qr 1 ../repo
  $ hg log
  changeset:   1:ed1b79f46b9a
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change foo
  
  changeset:   0:bbd179dfa0a7
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add foo
  

This used to abort: received changelog group is empty:

  $ hg pull -qr 1 ../repo

Test race condition with -r and -U (issue4707)

We pull '-U -r <name>' and the name change right after/during the changegroup emission.
We use http because http is better is our racy-est option.


  $ echo babar > ../repo/jungle
  $ cat <<EOF > ../repo/.hg/hgrc
  > [hooks]
  > outgoing.makecommit = hg ci -Am 'racy commit'; echo committed in pull-race
  > EOF
  $ hg serve -R ../repo -p $HGPORT2 -d --pid-file=../repo.pid
  $ cat ../repo.pid >> $DAEMON_PIDS
  $ hg pull --rev default --update http://localhost:$HGPORT2/
  pulling from http://localhost:$HGPORT2/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg log -G
  @  changeset:   2:effea6de0384
  |  tag:         tip
  |  parent:      0:bbd179dfa0a7
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     add bar
  |
  | o  changeset:   1:ed1b79f46b9a
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     change foo
  |
  o  changeset:   0:bbd179dfa0a7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     add foo
  

  $ cd ..